1. Field of the Invention
In general, the present invention relates to dollies, carts, booms, and cranes that are used to support and move video cameras and motion film cameras. More particularly, the present invention relates to dollies, cranes, carts, booms and cranes that have electronic motion controls.
2. Prior Art Description
In the past two decades, the use of motion film cameras have been nearly completely replaced by the use of video cameras. Video cameras are used to record motion pictures, television shows, commercials, and personal postings for social websites of the Internet.
Video cameras have the ability to zoom in and out. However, if a videographer wants the camera to pan, tilt, or otherwise change perspective, the video camera itself must be physically moved.
Often a camera is moved by manually lifting the camera and walking it to a new location. This method of camera movement has many disadvantages. Primary among these disadvantages are that the movement of the camera is not smooth and appears choppy. Secondly, the exact movement of the camera cannot be precisely reproduced. Accordingly, each time a scene is repeated, the recorded shot will be slightly different from all the other shots. Thirdly, the camera can only be moved within the range of the camera operator's arms.
In order to decrease the choppiness of a manually moved camera, cameras are often mounted on dollies or carts that can be rolled smoothly between locations. To increase the range of the camera, the camera is also often mounted to the end of an adjustable boom arm on the dolly. Such camera support systems are exemplified by U.S. Pat. No. 5,671,932 to Chapman, entitled Camera Crane and U.S. Pat. No. 7,037,006 to Chapman, entitled Camera Crane.
Although wheeled camera dollies and booms exist, and many of those prior art systems are motorized, the activation of the various motors is still done manually. That is, if a videographer wants a dolly to move forward, a cameraman presses a bottom on a motorized dolly and the dolly rolls forward. Likewise, if a videographer wants a camera to rise, a cameraman activates a motor on a boom that raises the camera. Since the activation of all motors that control camera position are manually controlled, an exact reproduction of movement cannot be precisely obtained. Each time a camera is moved, the cameraman will engage and disengage the various motor controls at slightly different times, thus resulting in slightly different camera angles each time a shot is repeated.
In many video productions, computer graphics and other special effects are added to a prerecorded image. This often requires a scene to be shot twice, using the exact same camera movements. One shot is for the principal actors. One shot is for the special effects. The two shots are then superimposed to create the final production shot. Often the special effects may be created on a set that is at a different location from the set of principal photography. Using manually operated dollies and booms, it is often very difficult to precisely reproduce the exact movements of a camera used during a particular shot.
A need therefore exists for a system and method of controlling the movements of a camera on a dolly or boom so that the precise movements of a camera can be recorded and then exactly reproduced at another time. In this manner, the exact positions of the camera can be duplicated in shot after shot. These needs are met by the present invention as described and claimed below.